In this research, nanoparticles of magnesium aluminate spinel were prepared by a modified sol-gel (pechini) method using Al(NO 3 ) 3 .9 H 2 O and Mg(NO 3 ) 2 .6H 2 O as the source of Al 3+ and Mg 2+ and different molar ratios of diethylene glycol (DEG) and succinic acid (C 4 H 6 O 4 ) as the gelling agent and complexer. The nanoparticles of magnesium aluminate spinel were characterization by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental analysis (EDS, MAPP) and N 2 adsorption-desorption (BET). The x-ray diffraction results confirmed the formation of single-phase magnesium aluminum spinel nanoparticles with a cubic crystal structure at 800 °C. The average crystallite’s sizes was calculated about 14 nm using the Debye –Scherrer equation. Scanning electron microscopy (SEM) was also showed that the prepared nanoparticles have a quasi - spherical morphology. In addition, the prepared nanoparticles were used as adsorbents to remove lead and cadmium contaminants from the heavy ion-containing water. Then, the effect of different parameters including pH, initial concentrations of lead and cadmium solutions, different adsorbent dose and adsorption time were investigated. To investigate the adsorption process, the adsorption kinetics for cadmium ions and equilibrium isotherms were investigated for two lead and cadmium ions, and it was found that the adsorption process for cadmium ion follows a second-order kinetic.